8/21/2012
Reed Hollinshead
ITD Communication
208-334-8881
reed.hollinshead@itd.idaho.gov
Bridge at Johnson Creek Airstrip near Yellow Pine to be replaced starting next week
VALLEY COUNTY - The narrow, wooden-plank bridge built on a railroad car decades ago at Johnson Creek Airstrip in Valley County, south of Yellow Pine, will be replaced starting Monday (Aug. 27), the Idaho Transportation Department announced. The bridge is important for community, recreational and emergency services functions.
Granite Excavation Inc., of Cascade, is the contractor on this $765,000 project.
Yellow Pine is a few hours northeast of Cascade.
Here's picture 1 and picture 2 of the existing bridge. Here's picture 1 and picture 2 of the bridge near flood condition and underwater in recent springs.
“The
bridge provides the only access to the Johnson Creek Airstrip, handling
both recreational and commercial traffic year-round,” said Dan Gorley
of the ITD Bridge Section. “The airstrip is an important community asset
providing air access during fire-fighting season and is designated as a
safe zone for Yellow Pine for evacuation purposes.”
The new
bridge will be one lane, like the old one, but wider. The new concrete
bridge will be located right next to and immediately downstream from the
current one. It will span 72 feet and be 18 feet wide at the bridge
deck.
“The bridge will also sit several feet higher in
elevation than the old bridge to safely accommodate high water or flood
conditions,” said Kyle Arnzen of the ITD Design Section for this region.
“The new bridge has been designed to exceed the 50-year-flood water
level. The water elevation can change by six or seven feet over the
course of the year depending on spring run-off, and often runs over the
top or reaches the deck of the old bridge.”
Traffic across the
old bridge, originally built in 1959, is weight-restricted to smaller
vehicles. The new structure will benefit forest service, aviation and
private-property owner interests. The bridge provides access to the
backcountry Johnson Creek Airstrip (4.5 miles south of Yellow Pine) and
to private land.
The project is expected to finish in late October. Traffic will continue to use the old
bridge while the new one is constructed. The old structure will be
removed once the new structure and approaches are complete.
Work is not anticipated at nights or on the weekend, but is not prohibited if needed.
No local roads will be closed, but drivers may experience delays during construction. One lane will be maintained.
“Some girders and abutments will be pre-cast to take advantage of accelerated bridge construction (ABC) techniques and reduce environmental impacts while quickening construction time,” said Gorley.